Molecular effects of copper on Mytilus galloprovincialis reproductive system.

This work aims to assess the effects induced by 24 h exposure to a sub-toxic copper concentration on reproductive system (gonads, spermatozoa and protamine-like proteins) of Mytilus galloprovincialis. Inductively coupled plasma-mass spectrometry indicated accumulation of this metal in gonads, spermatozoa and protamine-like proteins of exposed mussels. Further, RT-qPCR analyses showed altered expression levels of mt10 and protamine-like proteins genes in spermatozoa and gonads, respectively of exposed mussels. Protamine-like proteins, which represent the main basic component of sperm chromatin of this organism, showed, in exposed mussels, an higher DNA binding affinity and a different DNA binding mode. Moreover, an increased amount of NaCl was required for the release from sperm nuclei of PL-III, the main protamine-like proteins component. Finally, protamine-like proteins, extracted from exposed mussels promoted DNA oxidative damage, in the presence of H2 O2. These results demonstrate that also tolerable copper amount could affect protamine-like proteins properties and determine negative effects on reproductive system of this organism. These analyses could be useful to develop quick and efficient chromatin-based genotoxicity tests for pollution biomonitoring programs. This article is protected by copyright. All rights reserved.